When I was an undergrad, there was a professor about whom many undergrads said, "All he talks about is sex and death." When I took this professor, I found this wasn't the case: he talked about the literature. A lot of great literature is about sex and death. And a lot of the greatest of human themes involve sex and death.
Now as a teacher, I find it possible that some of my students think I obsess on sex and death (though perhaps not in that order). But I think I'm just dealing with the literature and presenting important themes.